a) Field of the invention
The present invention relates to a tub for grinding material on a rotary cutter. More particularly, the invention relates to an improved baffle system for such a tub.
b) Description of the prior art
Feed for livestock such as hay and the like are generally harvested into compact bales so that they are easier to transport and store. The compactness of such bales makes it not only difficult to mix the materials with grains or other types of feed but makes it also more difficult for the livestock to eat. Accordingly, various devices have been developed for grinding the baled feed so as to shred it into sizes more easily eatable by the livestock. Such devices frequently have a rotating tub-like container having a bottom floor under which is positioned a rotating rotary cutter to shred the feed. With such a device, the sidewalls of the container are rotated so as to drive the feed over the rotary cutter. Dry materials will feed through the opening of the rotary cutter reasonably well whereas damp materials and tightly compacted materials will often produce bridging over the opening and block entry of the materials into the rotary cutter.
A partial solution to this problem has been achieved by providing extension plates to the inside of the container sidewalls so as to augment feeding and/or breakup the bridging over the opening. However, because these plates are fixedly secured inside the sidewalls, they must be either placed permanently whether they are needed or not, or, put in place only when they are required which may cause installation problems when the tub is full. This problem has been addressed in U.S. Pat. No. 4,003,502 by providing selectably positionable blades attached to move with the sidewalls but extendable into or out of the container. However, because these blades are operated manually, there is a need for an operator to stay next to the grinder as the feed is shredded inside in order to push forward the blades as the load diminishes in size.
Also, because these blades advance radially in and out of the tub, the blocking of the rotation of one blade by a bridging effect may cause blocking of the whole rotating sidewall, hence causing damage either to the power means driving the walls or to the blade itself. Such a blocked blade may not be easy to retrieve by an operator without shutting off the machine.
Thus, there is a need for a grinding tub where the inner positionable blades automatically follow the contour of the feed as it diminishes in size. There is also a need for an inner blade to be resilient so that it does not block the rotation of the sidewall upon abutting against feed bridged over the rotary cutter opening.